The Analgesic Effects of the Thoracic Paravertebral Block on Post-percutaneous Nephrolithotripsy: A Retrospective Study.

INTRODUCTION: Percutaneous nephrolithotripsy (PCNL) is a minimally invasive procedure for treating large and complex kidney stones, often resulting in significant post-operative pain and increased opioid use. This study aims to compare pain scores between patients undergoing PCNL who did and did not receive a preoperative single-shot thoracic paravertebral block (PVB) at the post-anesthesia care unit (PACU) as the primary outcome. Secondary outcomes were patient-controlled analgesia (PCA) usage on post-operative day 1 (POD 1), total opioid consumption on PACU and POD 1, and post-operative nausea and vomiting (PONV). METHODS: A retrospective cohort study was conducted on the medical records of 341 patients who underwent PCNL from July 2014 to April 2016 in a single major academic center. PVB was administered at thoracic levels T7-9 using a volume of 20 cc of bupivacaine, ranging from 0.25% to 0.5%, to achieve the desired analgesic effect. RESULTS: After excluding 34 patients, the study included 123 in the no block (NB) group and 149 in the regional anesthesia (RA) group. There were no differences in demographics, including age, sex, weight and height, BMI, and indication for PCNL. The results revealed that the RA group experienced a statistically significant reduction in PCA usage in both crude and adjusted models (adjusted logistic regression analysis: OR = 0.19, 95% CI = 0.05-0.60; p = 0.008). However, there were no significant changes in total opioid consumption, pain scores, or incidents of PONV. CONCLUSION: The retrospective analysis did not reveal any discernible advantage in pain management associated with the use of PVB for post-PCNL analgesia, except for reducing the percentage of PCA narcotics used. Future investigations with larger sample sizes and meticulous control for surgical indications and complexity are imperative to accurately assess the efficacy of this block in the context of post-PCNL surgery.

Anterior spinal cord syndrome from a spinal epidural hematoma following removal of an epidural catheter.

PURPOSE: Spinal epidural hematoma (SEH) is a rare yet significant complication associated with neuraxial anesthesia. Here, we present the case of a 74-yr-old male who underwent open repair of an abdominal aortic aneurysm. Following the removal of an epidural catheter, the patient developed anterior spinal cord syndrome due to an SEH despite having a normal coagulation profile. CLINICAL FEATURES: This patient's neurologic presentation was marked by a loss of motor function while maintaining fine touch sensation distal to the spinal cord injury. Initial truncal computed tomography (CT) angiography failed to detect vascular compromise or diagnose the SEH. Subsequently, delayed magnetic resonance imaging (MRI) revealed a multilevel thoracic epidural hematoma, spinal cord infarction, and ischemia. Immediate surgical decompression was performed, but unfortunately, the patient had a poor outcome. CONCLUSION: Anterior spinal cord syndrome (ASCS) represents an uncommon neurologic manifestation of SEH, which is typically characterized by a triad of back pain and sensory and motor deficits. Although the initial CT scan was necessary to diagnose the postvascular surgery complication, it did not immediately detect the SEH. In cases of ASCS subsequent to thoracic epidural placement and removal, MRI is the preferred imaging modality for precise diagnosis and assessment of the need for surgical intervention. Despite adherence to anticoagulation guidelines, patients undergoing neuraxial anesthesia may face an elevated risk of developing SEH. Health care professionals should remain vigilant in monitoring for neurologic abnormalities following epidural catheter insertion or removal, particularly in the context of vascular surgery.

RéSUMé: OBJECTIF: L'hématome péridural rachidien est une complication rare mais importante associée à l'anesthésie neuraxiale. Nous présentons ici le cas d'un homme de 74 ans qui a bénéficié d'une réparation ouverte d'un anévrisme de l'aorte abdominale. Après le retrait d'un cathéter péridural, le patient a développé un syndrome médullaire antérieur dû à un hématome péridural rachidien malgré un profil de coagulation normal. CARACTéRISTIQUES CLINIQUES: La présentation neurologique de ce patient était marquée par une perte de la fonction motrice tout en conservant une sensation de toucher fine distale à la lésion médullaire. L'angiographie initiale par tomodensitométrie (TDM) n'a pas permis de détecter d'atteinte vasculaire ni de diagnostiquer un hématome péridural rachidien. Par la suite, une imagerie par résonance magnétique (IRM) retardée a révélé un hématome péridural thoracique à plusieurs niveaux, un infarctus médullaire et une ischémie. Une décompression chirurgicale immédiate a été réalisée, mais malheureusement, l'issue a été mauvaise pour le patient. CONCLUSION: Le syndrome médullaire antérieur représente une manifestation neurologique peu fréquente de l'hématome péridural rachidien, qui se caractérise généralement par une triade de maux de dos et de déficits sensoriels et moteurs. Bien que la tomodensitométrie initiale ait été nécessaire pour diagnostiquer la complication chirurgicale post-vasculaire, elle n'a pas immédiatement détecté l'hématome péridural rachidien. Dans les cas de syndromes médullaires antérieurs consécutifs à la pose et au retrait d'un cathéter péridural thoracique, l'IRM est la modalité d'imagerie privilégiée pour un diagnostic précis et une évaluation de la nécessité d'une intervention chirurgicale. Malgré le respect des directives d'anticoagulation, les patient·es bénéficiant d'une anesthésie neuraxiale peuvent faire face à un risque élevé de développer un hématome péridural rachidien. Les professionnel·les de la santé doivent demeurer vigilant·es dans le monitorage des anomalies neurologiques à la suite de l'insertion ou du retrait d'un cathéter péridural, en particulier dans le contexte d'une chirurgie vasculaire.

Intraoperative Ultrasound-Guided Transversus Abdominis Plane Catheters Placed for Post-operative Analgesia Following Pedicled Transverse Rectus Abdominis Myocutaneous Flap Breast Reconstruction: A Case Report.

Transverse rectus abdominis (TRAM) flap reconstruction of the breast is a procedure in which a flap of skin, fat, and underlying rectus abdominis muscle is used to reconstruct the breast. This procedure is commonly performed after mastectomy and results in significant pain at the donor abdominal site. We present this case of a 50-year-old female undergoing pedicled TRAM flap surgery in which ultrasound-guided transversus abdominis plane (TAP) catheters were placed intraoperatively, in a novel fashion: under ultrasound guidance, directly on the abdominal musculature, without overlying fat, subcutaneous tissue, or dressing. Our case-reported numeric pain scores ranged from 0-5/10 during postoperative days one to two. The patient's IV morphine requirement on postoperative days zero to two ranged between 1.34 mg to 2.6 mg per day, representing a significant decrease compared to literature-reported opioid consumption after such surgery. Her pain and opioid consumption increased significantly after catheter removal, suggesting the efficacy of our intraoperative TAP catheters.

Unilateral Right-Sided Ultrasound-Guided Erector Spinae Plane Block for Post-Laparoscopic Cholecystectomy Analgesia: A Randomized Control Trial.

Background: Post-laparoscopic cholecystectomy (LC) pain control is still an issue postoperatively. Objectives: We investigated the effectiveness of the unilateral right-side ultrasound-guided erector spinae plane block (ESPB) on post-LC pain intensity and opioid consumption. Methods: This is a parallel-arm randomized control trial on 62 adult patients with an American Society of Anesthesiologists (ASA) physical status ≤ 2 who underwent LC. The patients were randomized into 2 groups (the block group [BG] and the control group [CG]; n = 31 per group). BG received a single-shot right-sided T7 ESPB with 20 mL of 0.2% ropivacaine at arrival time in the post-anesthesia care unit (PACU). CG) received no regional anesthesia. Both groups received patient-controlled intravenous fentanyl and rescue meperidine for analgesia. The primary outcome was the pain intensity determined using a Numerical Rating Scale (NRS) in the first 24 hours after surgery. Secondary outcomes included total fentanyl and meperidine consumption within 24 hours. Results: Median pain scores were significantly higher in CG at rest and with coughing up to 12 hours after surgery compared with BG. Pain scores were higher in CG with a cough at 24 hours compared with BG (median 1 [interquartile range (IQR) 1, 2] vs. 1 [1, 0]; P = 0.0005). Total fentanyl consumption and meperidine consumption within 24 hours were significantly lower in BG compared with CG (median 60 µg [IQR 60, 90] vs 250 µg [90, 300]; P < 0.0001 and median 20 µg [IQR 10, 20] vs 25 [20, 25]; P = 0.002, respectively). Conclusions: A single-shot, right-sided, unilateral ESPB decreases post-LC opioid consumption and pain.

Characterization of mononeuropathy of the lateral cutaneous nerve of the calf.

INTRODUCTION/AIMS: Isolated injuries to the lateral cutaneous nerve of the calf (LCNC) branch of the common peroneal nerve can cause obscure chronic posterolateral knee and upper calf pain and sensory symptoms. Routine examination and electrodiagnostic testing do not detect them because the LCNC has no motor distribution and it is not interrogated by the typical peroneal nerve conduction study. There are only about 10 prior cases, thus scant physician awareness, so most LCNC injuries remain misdiagnosed or undiagnosed, hindering care. METHODS: We extracted pertinent records from seven patients with unexplained posterolateral knee/calf pain, six labeled as complex regional pain syndrome, to investigate for mononeuropathies. Patients were asked to outline their skin area with abnormal responses to pin self-examination independently. Three underwent an LCNC-specific electrodiagnostic study, and two had skin-biopsy epidermal innervation measured. Cadaver dissection of the posterior knee nerves helped identify potential entrapment sites. RESULTS: Initiating events included knee surgery (three), bracing (one), extensive kneeling (one), and other knee trauma. All pin-outlines included the published LCNC neurotome. One oftwo LCNC-specific electrodiagnostic studies revealed unilaterally absent potentials. Longitudinal, controlled skin biopsies documented profound LCNC-neurotome denervation then re-innervation contemporaneous with symptom recovery. Cadaver dissection identified the LCNC traversing through the dense fascia of the proximolateral gastrocnemius muscle insertion. DISCUSSION: Isolated LCNC mononeuropathy can cause unexplained posterolateral knee/calf pain syndromes. This series characterizes presentations and supports patient pin-mappings as a sensitive, globally available, low-cost diagnostic aid. Improved recognition may facilitate more rapid, accurate diagnosis and, thus, optimize management and improve outcomes.

High-Frequency Heart Rate Variability Index: A Prospective, Observational Trial Assessing Utility as a Marker for the Balance Between Analgesia and Nociception Under General Anesthesia.

BACKGROUND: Maintaining a balance between nociception and analgesia perioperatively reduces morbidity and improves outcomes. Current intraoperative analgesic strategies are based on subjective and nonspecific parameters. The high-frequency heart rate (HR) variability index is purported to assess the balance between nociception and analgesia in patients under general anesthesia. This prospective observational study investigated whether intraoperative changes in the high-frequency HR variability index correlate with clinically relevant nociceptive stimulation and the addition of analgesics. METHODS: Instantaneous and mean high-frequency HR variability indexes were measured continuously in 79 adult subjects undergoing general anesthesia for laparoscopic cholecystectomy. The indexes were compared just before and 2 minutes after direct laryngoscopy, orogastric tube placement, first skin incision, and abdominal insufflation and just before and 6 minutes after the administration of IV hydromorphone. RESULTS: Data from 65 subjects were included in the final analysis. The instantaneous index decreased after skin incision ([SEM], 58.7 [2.0] vs 47.5 [2.0]; P < .001) and abdominal insufflation (54.0 [2.0] vs 46.3 [2.0]; P = .002). There was no change in the instantaneous index after laryngoscopy (47.2 [2.2] vs 40.3 [2.3]; P = .026) and orogastric tube placement (49.8 [2.3] vs 45.4 [2.0]; P = .109). The instantaneous index increased after hydromorphone administration (58.2 [1.9] vs 64.8 [1.8]; P = .003). CONCLUSIONS: In adult subjects under general anesthesia for laparoscopic cholecystectomy, changes in the high-frequency HR variability index reflect alterations in the balance between nociception and analgesia. This index might be used intraoperatively to titrate analgesia for individual patients. Further testing is necessary to determine whether the intraoperative use of the index affects patient outcomes.

Intraoperative Placement of Paravertebral Catheters to Manage Postoperative Pain in Opioid-Dependent Patients After Thoracolumbar Spine Fusion Surgery: A Case Report.

We introduce a regional technique that involves the intraoperative placement of bilateral paravertebral catheters under direct visualization. The patient had stage IV lung cancer and was on chronic oxycodone therapy. He presented with a T10 metastatic lesion, and underwent spinal decompression with T7-L1 fusion and T10 corpectomy. Before fascial closure, catheters were advanced into the T10 paravertebral space under direct visualization by the surgeon bilaterally. Postoperatively, his pain was well controlled, and narcotic requirements were decreased. Our case report demonstrates that for patients undergoing posterior spine surgery, intraoperative placement of bilateral paravertebral catheters can be used to help manage postoperative pain.

Association between Bispectral Index System and airway obstruction: an observational prospective cohort analysis during third molar extractions.

BACKGROUND: Sedation regimes during oral procedures frequently associated with airway obstruction. The aim of this study was to define the association of Bispectral Index (BIS) to the depth of sedation and airway obstruction events. METHODS: Forty-seven patients between 14-21 years old, who were candidates for 3rd molar teeth extraction, were enrolled in this study. Patients received a total of 4 mg midazolam, 100 microgram fentanyl followed by titrated incremental propofol in 10 mg. The Richmond Agitation Sedation Score (RASS) was used to assess the depth of sedation. Each patient was attached to BIS monitor, while clinicians were not involved in the data collection process. Apnea, airway obstruction, O2 saturation, timing and interventions for controlling the situation were recorded. All data was synchronized with BIS data monitoring. RESULTS: The results show that 97.5% of cases were ASA 1 and 2, with average age of 17.3 years (±1.4) and a median BMI of 26.1. By using linear regression, for every unit decrease of median RASS (less than zero), there was 1.78 decrease in mean BIS Score (P=0.045, 95% CI: 0.08-3.47). The mean BIS Index (over 1 minute) with airway obstruction was 64 (±10.2), which was significantly lower than the BIS during non-airway obstruction (77±11.6), (P<0.001). By using logistic regression analysis, for every on unit increase in BIS Index, there is 24% decrease in odds in having airway obstruction (P=0.0009, 95% CI: 0.65-8.94). CONCLUSIONS: This study demonstrates that the BIS could potentially be a valid continuous monitoring method to avoid airway obstruction during sedation for patients undergoing dental surgery.

Effects of fresh gas flow, tidal volume, and charcoal filters on the washout of sevoflurane from the Datex Ohmeda (GE) Aisys, Aestiva/5, and Excel 210 SE Anesthesia Workstations.

PURPOSE: We investigated the effects of tidal volume (VT), fresh gas flow (FGF), and a charcoal filter in the inspiratory limb on the washout of sevoflurane from the following Datex Ohmeda (GE) Anesthesia Workstations (AWSs): Aisys, Aestiva/5, and Excel 210SE. METHODS: After equilibrating the AWSs with 2% sevoflurane, the anesthetic was discontinued, and the absorbent anesthesia breathing circuit (ABC), reservoir bag, and test lung were changed. The lung was ventilated with 350 or 200 mL·breath(-1), 15 breaths·min(-1), and a FGF of 10 L·min(-1) while the washout of sevoflurane was performed in triplicate using a calibrated Datex Ohmeda Capnomac Ultima™ and a calibrated MIRAN SapphIRe XL ambient air analyzer until the concentration was ≤ 10 parts per million (ppm). The effects of decreasing the FGF to 5 and 2 L·min(-1) after the initial washout and of a charcoal filter in the ABC were recorded separately. RESULTS: The median washout times with the Aisys AWS (14 min, P < 0.01) and the Aestiva/5 (17 min, P < 0.001) with VT 350 mL·breath(-1) were significantly less than that with the Excel 210SE (32 min). The mean (95% confidence interval) washout time with the Aisys increased to 23.5 (21.5 to 25.5) min with VT 200 mL·breath(-1) (P < 0.01). Decreasing the FGF from 10 to 5 and 2 L·min(-1) with the Aisys caused a rebound in sevoflurane concentration to ≥ 50 ppm. Placement of a charcoal filter in the inspiratory limb reduced the sevoflurane concentration to < 2 ppm in the Aisys and Aestiva/5 AWSs within two minutes. CONCLUSION: The GE AWSs should be purged with large FGFs and VTs ~350 mL·breath(-1) for ~25 min to achieve 10 ppm sevoflurane. The FGF should be maintained to avoid a rebound in anesthetic concentration. Charcoal filters rapidly decrease the anesthetic concentration to < 2 ppm.